In many situations, it can be desirable to know a location of a person inside an environment. For instance, in an emergency situation, the knowledge of the location of an employee in an environment (e.g., building) can be useful to provide assistance to the employee and/or to assist the employee in navigating out of the environment. Equipping persons (e.g., employees, emergency responder, and/or other persons) with a location device can enhance safety and productivity (e.g., by assisting the person in navigating the environment).
Previous approaches for location devices, typically known as personal navigation devices, however, may be expensive, unreliable, and/or inaccurate at locating and/or navigating inside an environment. For instance, such devices can include an inertial measurement unit (IMU) to estimate movement of a person, a Global Positioning System (GPS) component to establish a position of the person using GPS techniques using GPS signals, and/or a wireless component to estimate a location of the person using location estimation techniques (e.g., wireless signal triangulation). However, IMU measurements can have accumulated error (e.g., drift), GPS signals may be unavailable and/or intermittent inside an environment, and wireless signal based location estimation can be inaccurate due to refraction and/or reflection caused by structure of the environment. Some previous approaches resolve such inaccuracy and/or reliability problems using expensive equipment and technology. Accordingly, previous approaches for location devices may not be accurate, reliable, and/or cost effective.